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The traditional US phases
The AIA's March 2026 survey found that 97% of responding firm leaders still work within traditional design phases, with little variation by firm size or specialization. The sequence it names:
| Phase | What it is for |
|---|---|
| Schematic design | Establishing the concept and overall approach |
| Design development | Developing the chosen concept in more detail |
| Construction documents | Producing the drawings and specifications used to build |
| Bidding and negotiation | Helping the client select a contractor |
| Construction administration | Supporting the project while it is built |
The RIBA Plan of Work
UK practices commonly use the RIBA Plan of Work, which divides a project into eight stages numbered 0 to 7: strategic definition, preparation and briefing, concept design, spatial coordination, technical design, manufacturing and construction, handover, and use. The stage names give consultants and clients a shared language for where a project is.
Why phases drive fees
A phase is the unit that connects the work to the money. A firm agrees a fee, divides it across phases, and bills each as it progresses. That gives every phase three things worth recording: a fee share, a billing method, and the hours spent on it.
A phase is not the same as a task. A task is a piece of work inside a phase, such as producing a set of drawings. A phase is the stage that carries the fee. Phases also do not have to match the billing schedule one for one: a long phase can be split into several billable parts, or a short one can share an invoice.
Phases in software
When comparing tools, test whether one project can hold custom phases, each with its own billing method and progress, or whether every project is a single undifferentiated budget. The architecture project management software guide turns that into a five-step test.
In Rizqo, a phase is a billable stage with its own billing type (fixed, hourly or non-billable), its own amount and its own progress. Phases are optional, and the RIBA Plan of Work stages can be added in one step. Fixed fee or hourly explains how each phase's billing type is chosen, and architecture billing software shows how an invoice is built from them.